Monarch Butterflies Could Number 200 Million This Year

Newswise — COLLEGE STATION, March 1, 2011 – Despite recent cold snaps that brought record-setting low temperatures over much of Texas, the outlook for the annual Monarch butterfly invasion to the state looks promising “and better than expected,” says a Texas A&M University researcher.

Craig Wilson, a senior research associate in the Center for Mathematics and Science Education and a long-time butterfly enthusiast, says the numbers of Monarchs entering the state over the next few weeks should be very strong.

“The numbers are better than expected and the Monarch appears to have recovered to 2008-09 levels in their over-wintering sites in Mexico,” Wilson explains.

“The area of trees that are spread between about 12 sites where they hang, or what is termed festoon, for warmth has increased from about five acres last year to 10 acres this winter. That is very good news.

“Recent studies show their numbers this year could be about 200 million overall, which would be quite amazing since they were down almost 50 percent this time a year ago.”

Most of the Monarch reserves are in the Mexican state of Michoacan. It’s an area where Monarchs spend the winter and mate before heading north, and these breeding areas can contain 50 million butterflies within just a few acres, Wilson points out.

During their migration, Monarchs get about 70 percent of their food supply while flying their routes through Texas, and succeeding generations eventually fly 1,500 miles north to Canada.

While Monarchs are the most commonly seen butterfly in the region, Wilson says residents can also see Swallowtails, Skippers, Blues, Metal Marks, Whites and Sulphurs.

“There are about 450 different butterflies and over 550 types of moths that visit Texas, so there really are a lot of butterflies out there,” he adds.

He says the full migration patterns should begin soon, and Southwest residents should be able to see Monarchs and others in the next few weeks, adding that “several have already been spotted in the Friendswood area.”